Investigations have centered on understanding on a molecular level the intracellular regulation of metabolism in a neuroendocrine organ, the pineal gland. The topics of specific interest include the factors regulating cyclic AMP production, the function of cyclic AMP, the control of synthesis of pineal N-acetyltransferase activity, the control of activation and inactivation of this enzyme, the role of mRNA synthesis in the regulation of the activity of N-acetyltransferase activity, and the role of polyamine synthesis in the differentiation and hormonal regulation of the pineal gland. BIBLIOGRAPHIC REFERENCES: Klein, D.C., Kirk, K.L., Weller, J.L., Oka, T., Parfitt, A., and Owens, I. (1976): 2-Fluoro-L-Histidine: An inhibitor of enzyme induction. Molecular Pharmacology 12: 720-730. Buda, M. and Klein, D.C. (1978): N-Acetylation of biogenic amines in Biochemistry and Function of Amine Enzymes. (eds., E. Usdin and N. Weiner) (in press).